1. Field of the Invention
The present invention relates to a photoelectric conversion element configured to convert light energy into electric energy by means of photoelectric conversion.
2. Description of the Related Art
In order to provide improved resource saving and reduced costs, there is a demand for photoelectric conversion elements such as solar cells having a photoelectric conversion layer with a further reduced thickness. In a case of only reducing the thickness of the photoelectric conversion layer, this leads to a problem of reduced light absorption. In order to solve such a problem, as an indispensable technique, there is a demand for a technique for improving the light absorption of the photoelectric conversion layer.
As such a technique, there is a technique in which a texture structure is formed on the front face and/or the back face of the photoelectric conversion layer, configured to scatter input light and reflected light on the front face and/or the back face of the photoelectric conversion layer, thereby increasing the light path length in the photoelectric conversion layer. Also, there is a known technique for providing a periodic microstructure to such a photoelectric conversion element. In this case, by setting a condition such that the light passing through the photoelectric conversion layer is diffracted due to such a periodic microstructure, and such that total reflection of the reflected light occurs in the photoelectric conversion layer, such an arrangement allows the light to be confined in the photoelectric conversion layer, thereby providing improved photoelectric conversion efficiency.